Tubular heat transfer device

ABSTRACT

A heat transfer device including a tubular shell and a corrugated fin member inserted within the shell in which the cooling fluid flows axially through a plurality of passages formed by the corrugated fin member and the fluid to be cooled flows through a tortuous series of passages formed by the corrugated fin member.

United States Patent [72] Inventors Harry W. Leedham Kitchener, Ontario; Desmond M. Donaldson, Oakville, Ontario, both of, Canada [21] 'Appl. No. 748,525 [22] Filed July 29, 1968 [45] Patented June 15,1971 (73] Assignee Borg-Warner Corporation Chicago, ill.

[54] TUBULAR HEAT TRANSFER DEVICE 15 Claims, 10 Drawing Figs.

165/51 [51] Int. Cl F28d 9/02 [50] Field of Search 165/164,

[56] References Cited UNlTED STATES PATENTS 1,677,714 7/1928 Frease 165/141 X 1,998,974 4/1935 Sunday 165/165 X 2,316,273 4/1943 Meyer etal 165/141 2,420,757 5/1947 Neumann et al..... 165/157 2,661,934 12/1953 Stutz 165/154 Primary Examiner-Martin P. Schwadron Assistant Examiner-Theophi1 W. Streule Attorneys- Donald W. Banner, Lyle S. Motley, C. G. Stallings and William S. McCurry ABSTRACT: A heat transfer device including a tubular shell and a corrugated fin member inserted within the shell in which the cooling fluid flows axially through a plurality of passages formed by the corrugated fin member and the fluid to be cooled flows through a tortuous series of passages formed by the corrugated fin member.

PATENTED JUN? 5:971

SHEET 1 OF 2 mvemoms 055/110/1 0/1400/1 44050/1 #4 PVWLFEDA/AM ATTORNEY M. w

PATENTEU JUN] 51571 SHEET 2 OF 2 SUMMARY OF THE INVENTION This invention relates to heat transfer devices and more particularly to that type of heat transfer device in which one fluid is circulated in heat exchange relationship with another.

Heat transfer devices of this type are used in a number of applications. One possible application is to insert such a device in the line delivering cooled fluid from the radiator of a vehicle to the water pump and use the engine coolant to cool the hydraulic fluid from the automatic transmission. Other possible applications could be used to cool the engine lubricant, hydraulic fluids or power steering fluid.

A typical oil cooler for automatic transmissions is generally located in a side or bottomtank of the automobile radiator. It generally provides a passage for oil to flow from the inlet to the outlet and the oil is thus cooled by the coolant in the side or bottom tank of the radiator. The obvious disadvantage of such an arrangement is the additional cost involved in installing the unit in the radiator as well as the additional cost involved due to the increase in size of the radiator tank to provide for its accommodation of the oil cooler.

The present invention is designed to overcome such a disadvantage in that it is used in conjunction with a standard size automative radiator hose and doesnot involve modification of the radiator.

In addition to a cost problem, the space requirements of present-day automobiles present a serious problem. With the addition in the engine compartment of accessories such as air conditioning, power steering and power brakes, space in the engine compartment is at a premium. The present invention results in a substantial contribution toward easing this problem in that the extra space formerly devoted to an extension of the radiator either sideways or vertically for cooling the transmission oil can now be devoted to other purposes.

Another problem inherent in the use of present automatic transmission oil coolers is the necessity of manufacturing a number of different size and shape radiators for the same basic model car. For instance, a different model radiator andall the changes necessary in header tanks and connections would be required for cars equipped with standard transmissions than for those equipped with automatic transmissions due to the necessity of cooling the hydraulic fluid from the automatic transmission. The present invention eliminates this problem in that it allows auto manufacturers to use one standard size radiator and a standard set of connections and header tanks regardless of the type of transmission with which the vehicle is equipped. If the vehicle is equipped with an automatic transmission, the only change that must be made for transmission fluid cooling is to place the apparatus of the present invention in the radiator hose line which returns cooled fluid from the radiator to the water pump and attach suitable connections from this heat transfer apparatus to the transmission.

Circular tube and fin-type heat transfer devices are not, by themselves, new in the art but the present structure is deemed a substantial improvement over any shown in the art for a number of reasons.

In a heat transfer device in which one fluid is circulated in heat exchange relationship with another the effectiveness of the unit increases the more intimate the contact between the fluids. Also, as the amount of surface area contacted by both fluids is increased the effectiveness of the unit increases.

A standard method of constructing these devices is to provide a pair of concentric tubes one disposed within the other and a turbulizer separating them consisting of a sheet metal member formed with a plurality of generally rectangular corrugations bent to a circular form around the inner tubular member and abutting both tubes. One ofthe fluids is then axially directed through the inner tubular member and the other is axially directed through the annular space between the tubes with the turbulizer extending radially in heat transfer relationship with one or both tubes.

The present invention, as will be hereafter explained, provides a fin structure with fluid passages for one fluid internal to the fin member while the other fluid contacts the external surface of the fin thereby greatly increasing the intimacy of contact between the fluids while at the same time greatly increasing the total surface area contacted by both fluids resulting in a heat exchanger of substantially increased effectiveness.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a perspective view partially broken away of the assembled heat transfer device;

FIG. 2 is a top view of the sheet from which the fin member is formed;

FIG. 3 is a partial view in perspective of the formed fin member illustrated in FIG. 2;

FIG. 4 is a perspective view partially broken away of a second embodiment ofthe heat transfer device;

FIG. 5 is a perspective view partially broken away ofa third embodiment of the heat transfer device;

FIG. 6 is a top view of the sheet from which the fin member illustrated in FIG. 5 is formed;

FIG. 7 is a partial view in perspective of the formed fin member illustrated in FIG. 6;

FIG. 8 is a perspective view partially broken away of a fourth embodiment of the heat transfer device;

FIG. 9 is a top view of the sheet from which the fin member illustrated in FIG. 8 is formed;

FIG. I0 is a partial view in perspective of the formed fin member illustrated in FIG. 9.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to FIG. 1 a tubular :member 10 is illustrated and includes a pair of raised annular rings 11 and 12 extending circumferentially around the tubular member 10, and adapted to communicate fluid around an inner periphery 13 of the tubular member 10. A circular flat I5 is provided on ring 11 and defines an orifice 16. The flat 15 and orifice 16 are adapted to receive a fitting 17. A similar flat 18 is provided on ring 12 and defines an orifice 20 adapted to receive a fitting 21. Flared portions 22 and 23 are provided at either end of the tubular member 10 for the purpose of providing a leak-free seal when the tubular member is connected to suitable conduits.

As best seen in FIG. 2, the fin member 25 is formed from a sheet 26. The sheet 26 includes a plurality of vertically extending, adjacent columns A, B and C, each pair of columns A and B being separated from the next pair of columns A and B by the narrower column C. The vertical column A comprises a pair of depressions 27 and 28 oriented parallel to a horizontal axis 30 of the sheet 26. Vertical column A also includes a plurality of depressions 31 oriented at an angle to the horizontal axis 30 of the sheet 26. The upper most of these angular depressions 31 is shown to be connected to the horizontal depression 27. The lower most of the angular depressions 31 is shown connected to the horizontal depression 28. The horizontal depression 27 extends from a left edge 32 of vertical column IA toward a right edge 33 of column A which also forms the left edge of column B but stops short thereof. Likewise, the horizontal depression 28 extends from the left side 32 of column A almost to the right side 33 of column A but stops short of it.

The column B is similar to the column A in that it includes a pair of horizontal depressions 35 and 36 and a plurality of angular depressions 37. The essential difference between the columns A and B is that horizontal depression 35 extends from a right edge 38 of column B toward the left edge 33, but stops short of it. The horizontal depression 36 extends from the right side 38 of column B towards the left side 40 but stops short thereof.

The sheet 26 after being formed is then folded as best shown in FIG. 3, so that all vertical columns A and B are in contiguous relationship with each other and the column C separates adjacent folds. Horizontal depressions 28 and 36,

when folded thusly, form a fluid entrance chamber 41 adapted to receive fluid distributed around the inner periphery 13 of the tubular member 10 by raised annular ring 11. Horizontal depressions 27 and 35 when folded form a fluid exit chamber 42 adapted to communicate fluid to the raised annular ring 12. As can be seen in FIG. 3, the angular depressions 31 in column A coact with the angular depressions 37 in column B to form a fluid passage 43 defining a tortuous path extending generally radially inwardly and outwardly and extending between the entrance chamber 41 and the exit chamber 42. The fluid entrance chamber 41, a fluid passage 43 and a fluid exit chamber 42 have been shown and described for a single accordion fold 45. The structure is essentially the same for every fold of the fin member.

The folded sheet is then formed into a circular configuration and inserted into the tube member 10 such that the entrance chambers 41 are axially in line with the raised annular ring 11 and the exit chambers 42 are axially in line with the raised annular ring 12.

The fin member 25 is then allowed to expand radially until all of its outer circumference; namely, the vertical sections C, are in contact with the inner periphery 13 of the tubular member.

The fin member 25 is then bonded to the inner periphery 13 of the tubular member 10 at each lateral edge thereof. Additionally the fin member is bonded along each radial fold 45. The assembly thus provides a leakproofjoint between the fine ends and the tubular housing as well as between adjacent fin segments.

The resulting fin structure defines a plurality of fluid conduits 46 having a triangular cross section when viewed from an end of the tube member extending the length of the fin member each having a central axis parallel to the central axis of the tube member 10. A circular fluid conduit 47 is defined by apices 48 of the triangular conduits 46 and is concentric with the central axis of the tube member.

The operation of the device shown in FIG. 1 is essentially as follows: the transfer device is connected in any coolant line such as for example the line conveying cooled fluid from the radiator to the water pump of an automobile equipped with an automatic transmission.

A fluid conduit, not shown, is connected to fitting 17 for the purpose of communicating hydraulic fluid from the transmission to the heat transfer device to be cooled. Another fluid conduit is connected to fitting 21 and serves to return the cooled fluid from the heat transfer device to the transmission.

During operation ofthe vehicle, cooling fluid is passed from the radiator of the automobile axially through the transfer device by means of the triangular conduits 46 and the central conduit 47. Fluid from the transmission enters the heat transfer device through orifice l and, by virtue of the raised annular ring 11, is distributed around the inner periphery 13 of the tubular member and is supplied to each of the fluid entrance chambers 41. Since the fluid is under pressure, fluid introduced into each entrance chamber 41 is forced to flow through the corresponding tortuous path defined by fluid passage 43 and flows generally radially inwardly and outwardly in each fold 45. Upon traversing the fluid passage 43 the fluid is directed to the fluid exit chamber 42 corresponding with each fluid passage 43 and, by way of the raised annular ring portion 12 is communicated to the orifice 20. The fluid then leaves the heat transfer device and is returned to the automatic transmission.

It can readily be seen, that there has been a substantial increase in both intimacy of contact between the fluids and the total surface area touched by both fluids over prior art, circular heat transfer devices in that the cooling fluid is circulated around and across each fold in the fin member while the fluid to be cooled is circulated within the folds of the fin member. The result is a heat transfer device of substantially increased effectiveness.

If it is desired to subject the fluid to be cooled, in this instance the automatic transmission fluid, to more than one pass through the fin member, this can be accomplished by the embodiment shown in FIG. 4 termed a double pass heat exchanger. The essential difference between this embodiment and that shown in FIG. 1 is in the formation of the outer tubular member 50. The outer tubular member 50 includes a substantially semicircular raised annular portion 51 including a flat surface 52 defining an orifice 53 adapted to receive a fitting 55. A second substantially semicircular raised annular portion 56 is formed in the tube member 50 at the same end as the first semicircular portion 51 but rotated 180 from it. It includes a flat surface 57 defining. an orifice (not shown) adapted to be connected to a fitting 58. Atthe other end of the tubular member 50 is formed a raised circular annular chamber 60 adapted to place a plurality of fluid chambers in the upper half of the fin member 25 in communication with a plurality of fluid chambers in the lower half of fin member 25. The fin member used in the double pass device shown in FIG. 4 is identical to the one used in the single pass device shown in FIG. 1 and previously described.

The operation of the double pass" device differs from that of the single pass device as follows. Fluid is supplied to the heat transfer device through fitting 55 from the automatic transmission. The fluid is distributed to the fluid entrance chambers 41 in the upper half of the fin member 25. The fluid then passes through fluid passages 43 located in the upper half of the fin member which passages connect fluid chambers 41 and the corresponding fluid chambers 42 in the upper half of fin member 25. At this point, the fluid is placed in communication with the fluid chambers 42 in the lower half of fin structure at the same end of the tubular member which chambers now function as fluid entrance chambers. The fluid to be cooled then makes its second pass through the fin member 25 in a direction opposite to that which it transversed the first time this time passing through fluid passages 43 located in the lower half of the fin member 25. The fluid is then communicated to the fluid chambers 41 disposed in the lower half of the fin member 25 at the same end of the heat exchanger at which the fluid entered. These chambers now function as fluid exit chambers. The fluid is then communicated to the fitting 58 by means of the raised semicircular annular portion 56 and returns to the automatic transmission.

A third alternative embodiment is illustrated in FIG. 5 and is of the single pass type but allows for placing the inlet and outlet of the device toward the center of a tube member 65. A pair of raised annular chambers 66 and 67 are formed in the tube member 65 toward the center. Each annular chamber defines an orifice 68 and 69 respectively, each orifice adapted to receive a fitting 71 and 72 respectively. The fin member 73 is formed basically the same as the tin member 25 previously described, however, as illustrated in FIG. 6, vertical column C is formed with a pair of horizontal depressions 75 and 76 and a pair of narrower vertical depressions 77 and 78 each vertical depression in communication with a horizontal depression. When the fin member 73 is now folded. formed in a circular configuration, and inserted in the tube member 65, the vertical depressions 78 and 77 are in axial alignment with annular chambers 66 and 67 respectively. The fin member 73 defines a fluid chamber 80 and a fluid chamber 81 as illustrated in FIG. 7 disposed at opposite ends of the fin member and a fluid passage 82 connecting the chambers.

The operation of this embodiment of the heat transfer device is essentially the same as that shown in FIG. 1 and previously described. Fluid enters chamber 66 through orifice 68 and is communicated to fluid chambers 80 through vertical depressions 78. Fluid is then directed through the fluid passages 82 and is communicated to orifice 69 through fluid chamber 81, vertical depression 77, and annular chamber 67 as shown in FIG. 7.

A fourth alternative embodiment is shown in FIG. 8. The basic structure of the heat transfer devices previously illustrated is retained, however, the tube member 85 is of simpler construction and does not include raised annular chambers. The tube member 85 is provided with an orifice 36 and an orifice 87 each orifice adapted to receive suitable fittings 88 and 89-respectively. As shown in FIG. 9, the fin member 9! is formed substantially the same as the other fin members previously described and illustrated except that in vertical column C there is formed a pair of horizontal depressions 92 and 93 extending parallel to the horizontal axis of the fin member. Depression 92 is of the same width as and interconnects horizontal depression 94 in column B and depression 95 in column A. Likewise, depression 93 connects depression 96 in column A and depression 97 in column B. Horizontal depressions 96 and 97 together form a fluid entrance chamber as illustrated in FIG. 10 and depressions 94 and 95 form a fluid exit chamber. The horizontal depressions 93 formed in column C serve to place all fluid entrance chambers in communication with each other and with the orifice 86. The horizontal depressions 92 in column C serve to place all fluid exit chambers in communication with each other and with the orifice 87 in tube member 85.

Thus it has been shown that the present invention advantageously provides a heat transfer device of the type in which one fluid is circulated in heat exchange relationship with another which may be used to cool the hydraulic fluid of an automatic transmission of a motor vehicle.

It has also been shown that the present invention allows the automobile manufacturer to provide only one size radiator, header tank and fittings independent of whether the car is equipped with a standard or automatic transmission.

it has further been shown that the present invention provides a heat transfer device which provides a more intimate contact between the fluids and an increased surface area resulting in a unit of greatly increased effectiveness.

While certain preferred embodiments of the invention have been specifically disclosed for cooling the hydraulic fluid of an automatic transmission it is to be understood that the principles of the invention could be as easilyapplied to any heat transfer device in which one fluid is circulated in heat exchange relationship with another. Therefore, the invention is to be given its broadest interpretation within the scope of the following claims.

What we claim is:

1. A heat transfer device comprising a tubular outer member; a fin member disposed within said tubular member comprising a sheet member defining spaced apart and contiguous folds in a generally circular form such that the outer periphery of said fin member is in contact with the inner wall of said tubular member; said spaced apart folds defining axially oriented fluid passages for conducting a first fluid through said tubular member; said contiguous folds sealed along their intermediate length to define individual secondary fluid passages extending substantially along the length of said fin member and means for conducting a second fluid through said tubular member in heat exchange relationship with said first fluid.

2. A heat transfer device as in claim 1 in which each contiguous fold includes a pair of sidewalls, each of said sidewalls defining a plurality of spaced apart grooves, which when said sidewalls are in mating relationship, cooperate to define said secondary fluid passages.

3. A heat transfer device as in claim 2 in which each contiguous fold further defines a pair of fluid chambers, each of said chambers in communication with said secondary fluid passage defined by said contiguous fold.

4. A heat transfer device as in claim 1 in which a cross section of each spaced apart fold resembles a generally triangular configuration.

5. A heat transfer device as in claim 1 including first and second sets of secondary fluid passages; means adapted to receive fluid from an outside source and to communicate said fluid to said first set of said secondary fluid passages means adapted to place said first set of fluid passages in communication with said second set of secondary fluid passages; and

means adapted to receive fluid from said second set of secondary fluid passages and to deliver said fluid from said tubular member.

6. A heat transfer device comprising a tubular outer member; a fin member disposed within said tubular member comprising a sheet member defining spaced apart and contiguous folds in a generally circular form. such that he outer periphery of said fin member is in contact with the inner wall of said tubular member, said spaced apart folds defining a plurality of axially oriented primary fluid passages for conducting a first fluid through said tubular member, and said contiguous folds sealed along their intermediate length to define a plurality of secondary fluid passages; a plurality of fluid entrance chambers, each of said entrance chambers defined by said contiguous folds, each fluid entrance chamber in communication with its respective secondary fluid passage; a plurality of fluid exit chambers, each of said exit chambers defined by said contiguous folds, each of said exit chambers in communication with a respective secondary fluid passage; fluid distributing means adapted to receive fluid from. an outside source and to communicate said fluid to a plurality of said fluid entrance chambers; and fluid collection means adapted to receive fluid from a plurality of said fluid exit chambers and to communicate said fluid from said tubular member.

7. A heat transfer device as in claim 6 in which said fluid distributing means includes a raised annular ring defined by said tubular member.

8. A heat transfer device as in claim 6 in which said fluid distributing means includes depressions defined by said fin member.

9. A heat transfer device as in claim. 6 in which said fluid collection means includes a raised annular ring defined by said tubular member.

10. A heat transfer device as in claim 6 in which said fluid collection means includes depressions defined by said fin member.

11. A heat exchanger comprising a tubular shell member; a fin member disposed in said tubular shell member in contact with the inner wall of said tubular shell member folded to define a plurality of primary fluid passages extending axially with respect to said tubular shell member for the passage of a first fluid therethrough and to define a plurality of secondary fluid passages forming a tortuous path extending generally radially inwardly and outwardly along a substantial portion of the length of said fin member and means for conducting a second fluid into, through, and out of said tubular shell member; said primary and secondary fluid passages conducting said first and second fluids in heat exchange relationship with each other.

12, A heat exchanger as in claim 11 including a fluid inlet and a fluid outlet defined by a pair of orifices in communication with said tubular member.

13. A heat exchanger as in claim 12 including fluid distributing means disposed between and in communication with said fluid inlet and said secondary fluid passages whereby said fluid distributing means is adapted to communicate said second fluid from said fluid inlet to said secondary fluid passages.

14. A heat exchanger as in Claim 13 including fluid distributing means disposed between and in communication with said fluid outlet and said secondary passages whereby said fluid distributing means is adapted to communicate said second fluid from said secondary fluid passages to said fluid outlet.

15. A heat exchanger as in claim 11 in which said fluid passage defining means includes a fin member defining a plurality of folds, each fold spaced apart from the next fold such that said primary fluid passages are defined between said folds and said secondary fluid passages are sealed along their intermediate lengths and are defined internal to said folds. 

1. A heat transfer device comprising a tubular outer memBer; a fin member disposed within said tubular member comprising a sheet member defining spaced apart and contiguous folds in a generally circular form such that the outer periphery of said fin member is in contact with the inner wall of said tubular member; said spaced apart folds defining axially oriented fluid passages for conducting a first fluid through said tubular member; said contiguous folds sealed along their intermediate length to define individual secondary fluid passages extending substantially along the length of said fin member and means for conducting a second fluid through said tubular member in heat exchange relationship with said first fluid.
 2. A heat transfer device as in claim 1 in which each contiguous fold includes a pair of sidewalls, each of said sidewalls defining a plurality of spaced apart grooves, which when said sidewalls are in mating relationship, cooperate to define said secondary fluid passages.
 3. A heat transfer device as in claim 2 in which each contiguous fold further defines a pair of fluid chambers, each of said chambers in communication with said secondary fluid passage defined by said contiguous fold.
 4. A heat transfer device as in claim 1 in which a cross section of each spaced apart fold resembles a generally triangular configuration.
 5. A heat transfer device as in claim 1 including first and second sets of secondary fluid passages; means adapted to receive fluid from an outside source and to communicate said fluid to said first set of said secondary fluid passages means adapted to place said first set of fluid passages in communication with said second set of secondary fluid passages; and means adapted to receive fluid from said second set of secondary fluid passages and to deliver said fluid from said tubular member.
 6. A heat transfer device comprising a tubular outer member; a fin member disposed within said tubular member comprising a sheet member defining spaced apart and contiguous folds in a generally circular form such that he outer periphery of said fin member is in contact with the inner wall of said tubular member, said spaced apart folds defining a plurality of axially oriented primary fluid passages for conducting a first fluid through said tubular member, and said contiguous folds sealed along their intermediate length to define a plurality of secondary fluid passages; a plurality of fluid entrance chambers, each of said entrance chambers defined by said contiguous folds, each fluid entrance chamber in communication with its respective secondary fluid passage; a plurality of fluid exit chambers, each of said exit chambers defined by said contiguous folds, each of said exit chambers in communication with a respective secondary fluid passage; fluid distributing means adapted to receive fluid from an outside source and to communicate said fluid to a plurality of said fluid entrance chambers; and fluid collection means adapted to receive fluid from a plurality of said fluid exit chambers and to communicate said fluid from said tubular member.
 7. A heat transfer device as in claim 6 in which said fluid distributing means includes a raised annular ring defined by said tubular member.
 8. A heat transfer device as in claim 6 in which said fluid distributing means includes depressions defined by said fin member.
 9. A heat transfer device as in claim 6 in which said fluid collection means includes a raised annular ring defined by said tubular member.
 10. A heat transfer device as in claim 6 in which said fluid collection means includes depressions defined by said fin member.
 11. A heat exchanger comprising a tubular shell member; a fin member disposed in said tubular shell member in contact with the inner wall of said tubular shell member folded to define a plurality of primary fluid passages extending axially with respect to said tubular shell member for the passage of a first fluid therethrough and to define a plurality of secondary fluid passages forming a tortuous path extending generally rAdially inwardly and outwardly along a substantial portion of the length of said fin member and means for conducting a second fluid into, through, and out of said tubular shell member; said primary and secondary fluid passages conducting said first and second fluids in heat exchange relationship with each other. 12, A heat exchanger as in claim 11 including a fluid inlet and a fluid outlet defined by a pair of orifices in communication with said tubular member.
 13. A heat exchanger as in claim 12 including fluid distributing means disposed between and in communication with said fluid inlet and said secondary fluid passages whereby said fluid distributing means is adapted to communicate said second fluid from said fluid inlet to said secondary fluid passages.
 14. A heat exchanger as in Claim 13 including fluid distributing means disposed between and in communication with said fluid outlet and said secondary passages whereby said fluid distributing means is adapted to communicate said second fluid from said secondary fluid passages to said fluid outlet.
 15. A heat exchanger as in claim 11 in which said fluid passage defining means includes a fin member defining a plurality of folds, each fold spaced apart from the next fold such that said primary fluid passages are defined between said folds and said secondary fluid passages are sealed along their intermediate lengths and are defined internal to said folds. 